The invention pertains to a system for the secure transfer of material and in particular of hazardous material from an isolated environment to a storage container external to that environment. Such material can be a hazardous radioactive or toxic material that needs to be transferred from a containment enclosure such as a closed storage basin or room to a portable storage vessel. A containment cell will typically have a wall or floor with a transfer port for removal of the objectionable material to the portable vessel. It is important that the transfer equipment enable secure transfer of the material so as to avoid contamination of the surrounding environment. This gives rise to a requirement for a system for the secure transfer of the material from the containment area to the storage vessel.